1. Field of the Invention
The present invention relates to an internal combustion engine, and more particularly, to a crankshaftless internal combustion engine capable of remarkably reducing even noxious exhaust gas while remarkably increasing a fuel efficiency improvement rate by transferring a reciprocating movement of a piston depending on a stroke cycle to power train power or accessory power shaftlessly and variably driving a cylinder.
2. Description of Related Art
In general, in an internal combustion engine such as a gasoline engine or a diesel engine, a piston reciprocates depending on a stroke cycle and the reciprocation movement is converted into rotational toque by using a crank shaft that rotates by receiving the reciprocation.
As described above, rotational force of the crank shaft pulls out engine power and transfers the engine power to a power train or is used as power for driving an accessory such as an electronic apparatus, and as a result, the rotational force serves as a most fundamental component in a power system of the internal combustion engine.
However, in the crank shaft, a change in a volume in a combustion chamber to a change in a crank angle around a top dead point in a reciprocating stroke cycle of a piston is small, and as a result, high-pressure and high-temperature combustion gas in the combustion chamber cannot but be spilled or heat-transferred to a wall surface of the piston.
The piston operation consequently reduces combustion efficiency to deteriorate fuel efficiency and increase noxious exhaust gas, and as a result, there is a fundamental limit which is not suitable even for high oil prices and strengthened environmental regulations.
However, improvement of the fuel efficiency and reduction of the noxious exhaust gas should be implemented even in the internal combustion engine due to the high oil prices and the strengthened environmental regulations.
As the example, there is a variable cylinder deactivation engine.
In this case, by changing a cylinder driving scheme in which fuel is excessively consumed more than necessary as all the cylinders are simultaneously driven even though all cylinders need not to be driven at a low output, the improvement of the fuel efficiency and the reduction of the noxious exhaust gas can be achieved without changing a configuration of the internal combustion engine.
In general, the crank shaft is necessarily applied even to the variable cylinder deactivation engine having the above engine control scheme.
As a result, heat cannot but be transferred between the high-pressure and high-temperature combustion gas and the piston due to a change in volume in the combustion chamber which is relatively small than the change in crank angle around the top dead point even in the variable cylinder deactivation engine.
Therefore, when the internal combustion engine implements power transfer without the crank shaft which causes heat transfer through the piston and the resulting deterioration in the fuel efficiency, the fuel efficiency can be prevented from deteriorating due to the crank shaft.
Moreover, when the crankshaftless internal combustion engine is cylinder-controlled by a variable cylinder scheme, the fuel efficiency can be further prevented from deteriorating while an increase in the noxious exhaust gas is suppressed.
Further, as another method for improving the fuel efficiency, a variable compression ratio is controlled.
In this case, the fuel efficiency is improved by increasing a compression ratio of a mixer in a low load condition of an engine, while the engine output is improved as well as knocking is prevented from occurring by reducing the compression ratio of the mixer in a high load condition of the engine.
However, the variable compression ratio control further requires a separate variable compressor mechanism for differentiating the height of the piston.
As described above, the fuel efficiency of the internal combustion engine can be improved in various methods, and as a result, the fuel efficiency is maximally prevented from deteriorating and simultaneously, the noxious exhaust gas is also reduced together, thereby more easily conforming to the high oil prices and the strengthened environmental regulations.
However, an aspect of hardware in which a compression ratio varies simultaneously while the internal combustion engine is configured without the crank shaft and an aspect of software in which the hardware is controlled by the variable cylinder scheme cannot but be complicated due to various factors.
Therefore, the complicated aspects cannot but make it more difficult to commercialize the internal combustion engine capable of controlling the engine by the variable cylinder scheme without the crank shaft.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.